As LSIs and 3D memories become finer and more multilayered, an increase in metal wiring delay has become an important problem. To reduce wiring delay, it is important to reduce wiring resistance and interwiring capacity. To reduce wiring resistance, low-resistance materials such as Cu have been put into practical use. However, even Cu wiring has problems such as stress migration- or electromigration-induced degradation of reliability and size effect-induced increase in electric resistivity. Therefore, there has been a demand for wiring materials with lower resistivity and higher current density tolerance.
Next-generation wiring materials expected to have lower resistance and higher reliability include carbon-based materials, such as carbon nanotubes and graphene, which have excellent physical properties such as high current density tolerance, high electrical conductivity, and high thermal conductivity. Attention is given to applications of such carbon-based materials.